Air conditioning system



July 2, 1940. c. F. BEELER v 2,206,445

AIR CONDITIONING `SYSTEM CHAR LES F.' .BEELER ATTORNEY July 2, 1940.

c. F. BEELER 2,205,445

AIR CONDITIONING sYsIEu l Filed oct. 2o, 1937 :s sheets-sheet 2 (Il 50 5l -o-f I fa -o-C CHARLES F. BEELER ATTORNEY u July 2, 1940. C. F. BEELER v2,203,445

AIR CONDITIONING SYSTEM Filed Oct. 20, 1937 3 Sheets-Sheet 3 INVENTOR CHAR LES F BEELER @l '1111, BY ma @www ATTORNEY Patented July 2, 1946 AIE CONDITIONING SYSTEM Charles F. Beeler, Highland Parli, Mich., assignor.,v by mesne assignments, to Chrysler Corporation, Highland Park, Mich., a corporation of Ecla- Ware Application October ZIB, 1937, Serial No. 169,936

2 Claims.

My present invention relates to an improvement in air conditioning units having incorporated therein improved means for controlling the humidity and temperature of the enclosure with 5 which the unit is associated. The purpose of my invention is to render the control of conditions more accurate and reliable and to lessen the cost of air conditioning. In accordance with. my invention the control of temperature and humidity may often be accomplished by increasing or decreasing the amount of fresh air sent through the unit thereby lessening the amount of refrigeration or heating by mechanical means.

Further objects and advantages of my invention will be apparent from the following description taken in connection with the accompanying `drawings wherein Fig- 1 is a vertical section taken through the air conditioning unit along the line I-I of Fig. 2, looking in the direction of the arrows; Fig. 2 is a horizontal cross-section through the unit taken along line 2--2 of Fig. 1, looking in the direction of the arrows; Fig. 3 is a vertical section taken through the-unit along line 3 3 of Fig. 1, looking in the direction of the arrows; Fig. 4 is a schematic diagram of the unit showing the same with the dampers set in one position so that all the air passing through the unit is recirculated air; Fig. 5 shows a second position of the dampers in'which all of the air passing through the unit is fresh air which remains at its natural temperature and humidity; Fig. 6 shows a third disposition of the dampers in which all the air is recirculated air passing' through a cooling and humidfying spray; Fig. 'i

3;, shows a fourth position of the dampers in which freshA air is introduced without change of state and recirculated air passes through the spray;

Fig. 8 shows a fifth position of the dampers in which all of the air is recirculated air passing -through a heating coil; Fig. 9 shows a sixth position of the dampers in whichfresh air is passed through the cooling coil and a certain amount of recirculated air is admitted; Fig. 10 shows a seventh position of the dampers in which recirculated air passes through the spray; and Flgfll is a wiring diagram of the unit showing the means for controlling the dampers to operate in the manner described.

In Fig. l there is disclosed a unit I0 compris- 5,0 ing a fresh air passage II having access to air outside the enclosure and a recirculated air passage I' through which air from the enclosure is drawn, the unit having a blower I3 therein by means of which the airis drawn into the unit and 55 ejected through a discharge passage Il. The unit is supported on legs I5, I6 to which are attached motor supports l1 and I8 supporting damper motors I9, 20 and 2|. Beneath the unit there is situated a compressor 25 which compresses a refrigerating medium into discharge 5 pipe 26. The discharge pipe' is provided with a solenoid valve 21 which prevents the refrigerant from passing into a water-cooled condenser 28, the refrigerant then passing into a branch discharge pipe 29 also provided with'a solenoid valve 10 30 which leads to heating coils 3l and 32 connected by a header 33 and a return header (not shown). The refrigerant gas which passes through the heating coils :ilv and 32 passes through pipe 3i into the water-cooled condenser 15 28. The condenser is supplied with cooling water through pipes 35 and 36, the flow of cooling water being preferably controlled by a thermally responsive valve so as to economlze on water consumption (such valves being well-known in the 20 art and hence not shown). The cooled liquefied refrigerant then flows through pipe 31 to an expansion valve 38 admitting liquidinto the cooling coil 39 where by expansion a low temperature is realized. The gas is then drawn through suc- 25 i tion pipe ttl into the compressor and the cycle of refrigeration repeated.

It is apparent from Figs. 1 and 2 that the heating and cooling coils are situated within the. unit in such position that normally only recir- 30 culated air could be drawn through them. However, a study of Figs. 5 to 10 shows the manner in which fresh air or recirculated air can be' drawn through the coils in various fashions to accomplish various purposes. The following de` 35 scription will, serve toY clarify lthe operation `of .A theunit in order to economize on power coni sumption by accomplishing the control of heating, cooling, humidifying or dehumidlfying by l means of controlling the amount and direction Vofair ow. l This control is accomplished by means" of* dampers shown in Figs. 1, 2 and 3. In the fresh air passage I I there is situated a damper which prevents the entrance of fresh air into the unit 45 when in closed position. Damper 50 when-in open position permits the entrance of fresh air and a second damper 5I causes fresh air to pass directly into the room when in open position and to\pass vertically downward through vthe cooling 50 I coil through opening 52 when in closed position. A set of face dampers 53 are situated at the ve11- trance of the recirculated air passage I2 and prevent theentrance of recirculated air to the cooling coil 39 when in closed position. A set ofy 55 20 ers 59, 60 and 5I.

three rear dampers 54 are located behind the cooling coil 39 and permit air to pass through the cooling coil from front to rear when dampers 58 and 54 are both open. Dampers 54 form with 5 the face dampers 53 the walls of a passage causing fresh air to pass downward through the cooling coil 39 when both sets of dampers are closed. At each side of the recirculated air passage I2 there are recirculated air by-pass passages 55 and 58 leading recirculated air to heating coils 3| and 32, respectively. The entrance to passage 55 is controlled by a set of three dampers 51 and a similar set of three dampers 58 acting in unison therewith controls the entrance to passage 56.

In front of heating coil 3| there are two dampers together by a link 59, so that when dampers 51 are open dampers A53 and 54 will be in closed position and vice versa. Situated beneath the cooling coil 39 is a passage 10 through which air directed downwardly through the cooling coil 39 can be by-passed around dampers 54 when damper 1I is in open position. Damper motor 29 ls connected to damper l1I by a link 12, which is in turn connected to damper 6I by a link 13, which is in turn connected to damper 5I by a link 14. When dampers 1I and 6I are in closed vposition damper 5| will be in open position and vice versa. Damper motor 2| is connected to dampers 59 and 69 by a link 15 which is iii/turn connected to damper 50 by a link 19. When o damper 50 is closed dampers 59 and 89 will be open and vice versa.

Referring to Fig. 4 the apparatus is shown diagrammatically in one position, for purposes,

of illustration passage 59 and heating coil 32 having been eliminated since the operation thereof is identical to the operation of passage 55 and heating coil 8|. In this view damper 50 is closed, shutting oil.' the supply of fresh air. Dampers 53 are closed, shutting o the ow of recirculated air through cooling coil 39. Dampers 51 are open thereby limiting the operation of the unit to treatment of return air. Since damper 59 is in closed position dampers 59 and 59 are in open position. Also, dampers 1I and 5I are in closed position and damper 5| in open position. The

flow of air through the heating coil is therefore limited to the amount which can pass through the open dampers 59 and 59.

In Fig. 5 the dampers remain the same except 60 that dampers 59, 59 and 59 are reversed in position. 'I'his causes the complete blocking oi of recirculated air and an unrestricted now of fresh air through passage II. In Fig. 6 the fresh air passage II is blocked of! and the passage 55 is likewise blocked oil.' while the passage I2 directly throughv the cooling coil is open for the admission *of recirculated air to the cooling coil.

Fig. "I discloses the dampers in such position that the freshair passage is entirely open and the recirculated air e I2 is also entirely open so that the air is divided between the two The air flowing through passage I2 flows through coil 39 in thenarrow direction, which is to say that in one embodiment of my invention the air passes through three rows of tubes. Due to the resistance of the coil the amount of air flowing through one passage would be substantially the same as that flowing through the other passage. Fig. 8 discloses the dampers in such position that all the air admitted to the unit is recirculated air which passes through the heating coils 3| and 32. Fig. 9 shows the dampers in such position that air is entering through the fresh air passage II and traversing the wide dimension of the coil which in the same embodiment of my invention as mentioned above means that the air passes through nine rows of coils. Recirculated air also passes through the passage 55 in an amount as permitted by the-open damper 5I. Fig. 10 discloses the dampers in such position that all of the air is recirculated air passing through the passage I2 in the narrow direction of the coil. The'purpose of each damper position will be more fully explained while explaining the control means for operating the dampers and other elements of the unit.

In addition to the cooling and heating coils previously described there is also placed in the unit a pipe provided with spray nozzles 8| by means of which a fine mist may be created in the passage I2 so that air passing through this passage has its vapor content increased and is lowered in temperature by the evaporative cooling of the water sprayed into the passage.

Referring to Fig. l1 there is set forth a wiring diagram for the above form of my invention. In this diagram the fresh air damper motor 2|, the face and by-pass damper motor I9 and the seasonal dampez motor 20 are indicated schematically and are shown as being provided with a plurality of cams for the purpose of making contacts at various positions of the dampers. A motor is provided for a motorized steam valve which may be operated to admit steam to the ordinary radiators or other heating means of a heating system (not shown). The valve 30 between the compressor and the coils 3| and 32 and the valve 21 between the compressor and the water-cooled condenser are shown in their relative positions, there being no control for the lspray through pipe 89 since the same is intended to operate at all times unless manually shut olf during seasons of high humidity.

In order to explain the operation of the system let us assume that itis winter and the room is at 74'd. b., 50% r. h. and the room thermostat 98 and room humidostat 81 indicate that this condition is satisfactory. 'I'he outside air is lower in both wet bulb temperature and absolute humidity than the room condition; for example, 42 d. b., 30% r. h. If the switch 88 is now closed the motor 89 of blower I3 will operate to draw air through the unit since the fan switch causes current to pass from the volt supply 90 through the switch 88 and motor 39 back to supply. Since we have assumed that room conditions are satisfactory the blower will merely circulate air through the unit as setfor'th in Fig. 4. 'Ihe compressor will not be running and the reheat coil 3| will therefore have no eiect on the air passing through the passage 55, the amount of air recirculated being, by way of example, 1000 cubic feet per minute.

If the room temperature falls the thermostat 98 will make at the low contact 9| with the result that current passes from the 24 volt battery 92 through wire 83, wire 94, wire 95,l thermostatic element 99, low contact 9|, wire 91, wire 98, cam contactor 99 on the motor 85, through the steam valve motor 85, and wire |99 to wire I 0| leading back to 92. Thus the motor will be started to open the steam' valve. In the zero or closed position of the motor, cam 99 is the only cam to make contact. 'Ihis cam carries current until the motor has rotated 4, but at 2 of rotation cam |05 will also close. Thus the circuit before noted and the circuit direct from wire through wire |06, Wire |01, cam |05 and the motor 85 carry current in parallel through the motor from 2 to 4 of rotation. At 4 cam 99 breaks contact and the motor runs on the circuit through cam |05 to the 180 position of the motor. Wire 91 Will still remain energized through the thermostat contact 9| and current will pass through wire |08, relay coil |09, wire H0, cam contact and wire |2 back to the battery, as soon as cam makes contact at 178 of rotation. By thus energizing coil |09 the switch I3 is held open so that current cannot energize the motor through cam ||4. Thus the motor remains in 180 position until the thermostat low 'contact 9| is broken. Since we are assuming a winter condition with steam on and the compressor not running, the air will continue to be recirculated through the unit, all of the air being recirculated air passing through passage 55 as seen in Fig. 4.

When the temperature in the room rises enough to break contact at 9| relay |09 is no longer energized so that current can flow through cam ||4 causing the motor to continue moving in the same direction toward the 360 or zero position. At 182 cam |05 is again closed carrying current to the motor in parallel with cam |4 until at 184 the current can no longer pass through cam ||4 and the motoris entirely fed through cam |05 from there on until the 358 position is reached. At 358 cam |5 breaks contact, thus opening a circuit through wire 2, cam ||5, wire H6, switch ||1, wire ||8, relay l|9 and wire |20 back to battery 92 which deenergizes the relay ||9, opening switch |2| and causing the fan motor to stop so that the fan is no longer circulating air through the room. This completes the control of the apparatus during the operation of heating by recirculating the air over radiators located in the room.

Now if the temperature rises element 96 of thermostat 86 will make the high lcontact |25 and current will now pass from 96 vthrough |25, through a switch |26 normally in contact with a wire |21, lthrough the wire |28, cam |29, motor 2|, and wire |30 to the battery 92. Thus the motor 2| starts and as withr respect to the motor 85 is driven to `180 by current passing through wire 94, wire |3I, and cam |32 to the motor 2|. The fresh air damper- 50 is noti1 wide open as shown in Fig. 5 and the reversely linked dampers 59 and 60 are closed so that all of the` air, for example, 1000 cfm. is fresh air passing through passage As long as the thermostatic contact `|25 is made, relay |33 will keep switch |34 in open position preventing current from passing through wire |35 and cam |36. However, when the outside air has reduced the room temperature enough to break contact |25 the relay |33 will be de-energized, thus starting the motor to travel from 180, the traveling being continued to 360 by current passing through cam |32, thus closing oi the fresh air.

I have thus described a method of controlling the temperature in the room during winter, having shown whathappens to correct both falling and rising temperatures. Correction must V,also

be made in cases of rising and falling humidties, for which the room humidostat 'been provided. It may be seen that the high contact |40 of humidostat 81 feeds current to line |21 just as the high contact |25 of thermostat 88 fed current to line |21. This means that as long as the temperature, or the humidity, or both the temperature and humidity, is too high line |21 will be carrying current so that the fresh air damper must be opening or standing open. When both high contacts are broken relay |33 will be deenergized causing the fresh air damper to be closing or standing closed. If the humidity falls too low then the low contact |4| of humidostat 81 will be closed and ,current will 'fiow through line |42 and line |43 to cam |44 of motor |9, through the motor, and line |45 to ground.

Again the cam |46, 'corresponding to camsv |05 and |32, will drive .the motor to 180. At this point the dampers are in the positions shown in Fig. 6, the face dampers 53 being open, the rear dampers 54 being openand all other passages being closed. Therefore all of the air, for example, 1000 cfm. will be passing through passage I2 and since the compressor is not operating and the spray through pipe 80 is continuous the air will be humidied. As soon as the humidity has risen to the control point contact |4| will Ibreak so that relay |50 will be deenergized causing current to ow through wire |5| switch |52, and cam |53 and the motor 9 will start closing the face and rear dampers.

Thus I have control means for both falling or rising temperatures and humidity during the winter months. When neither temperature nor humidity is different from the desired con-dition all motors will be standing at zero or off position, the fresh air passage and by-pass passage will be closed, and the air will be recirculated without treatment. If the vtemperature drops the steam valve will be opened and the air will be heated without treatment as to humidity. If the ltemperature rises too high, the fresh air passage will open, the recirculated air passage will close, the steam valve will be closed, and fresh air will be used to lower the temperature of the room as well as to ventilate as shown in Fig. 5. If the humidity is too low and the temperature agreeable, the fresh air passage will be closed, the passage 55 will be closed and room air will be recirculated through the hurnidifying` heatingl may take place simultaneously with .any

position of 'the dampers causedby the humidostat, which means the equipment could be ventilating and heating; humidifying and heating, or y* recirculatlng .and heating. I have thus shown a method of controlling the temperature -and humidity in an enclosure when there is avail-v able a free source of 'cooling and dehumidifying, which is the outside air.

During the summer when the outside air, instead of being at 42fd. b., 30% r. h. as in winter, is at, for. example, 83 d. b. and 70%r. h., if the temperaturev or humidity in the room rises-above l desired. conditions the highcontact of either thermostat 86 or humidostat 81 is made with the provided a thermostat |60 and a humidostat |6| which are connected in the circuit as follows: From wire 94 a wire I 62 leads to the thermostatic element |63 and from wire 94 a wire |64 leads to the humidostatic element |65. These elements are designed to make contact with a wire |66 on the high side of both instruments which wire is connected to Wire |61 leading to cam |68 of motory 20, the current passing through the motor and wire |69 to 92. The rise in inside temperature results in current being carried to the motor which causes the motor to start toward 180 and to stop at 180 through the medium of cams corresponding to those previously described for each other motor. When cam |10 is energized current is led from Wire |1| through wires |12 and |13 to solenoid |14, thus breaking the contact of switch |26 with wire |21 and causing switch |26 to contact wire which causes the high contact of thermostat 86 to control motor I9 instead of motor 2|. It also energizes solenoid |16 through wire |11 and wire |18 so that solenoid |80 will be energized to-close switch |8| which causes current to pass from battery 90 through wire |82 to wire |83 which at the point indicated by the arrow leads into control circuits comprising elements such as high and low pressure cut-outs, starting switches, etc., for the compressor motor, the opposite side of the circuit being indicated by wire |84. Such control circuits for compressor motors are well known and would serve no purpose if illustrated in the present drawings. The motors |19 and 20 when rotated to 180 have caused the dampers to assume the positions shown in Fig. 9 thereby causing fresh air to be drawn through the long dimension of the coil 39 and recirculated air to pass through passage 55 in the amounts of about 300 to 600 cfm. respectively. Let us suppose that both the temperature and humidity are now too high. This will keep motor 2| at 180 and the compressor running so that the small amount of air being brought through the long dimension of the coil will be brought to a dew point well below that of the room with the result that room air is being recirculated and mixed with cold, dry, fresh air. If the room temperature now becomes too cold the thermostat 86 will make contact at 9| then the heating motor 85 will be operated to reheat the room. Since switch |8| is closed 110 volt current through line |85, solenoid |86,

line |83 and the controls will'bring switch IIT to its lower position thereby bringing current through wire ||6 to solenoid |81 and through wire |88 to wire |06. 110 volt current will ow through wire |90, switch |9| and wire |92 through solenoid valve instead of through wire |93 and solenoid valve 21; thus solenoid valve 30 is opened and solenoid valve 21 closed causing hot gas from the compressor to go through the reheat coils 3| and 32. If the compressor stops solenoid |86 Will allow current to start the steam heat as previously explained. If, however, while the compressor is running the reheat coils raise the temperature suiliciently to break contact 9| then motor 85 will return to closed position and the valves 30 and 21 will be reversed in operation thereby permitting hot gas to go directly to the water cooled condenser.

4 thermostat 86 it will be seen that current cannot flow through solenoid |14 because the contacts of solenoid |81 are open. However since the hu- .midity has been corrected, in other Words, contact is broken, then motor 2| will go to zero position, the fresh air damper will be closed and solenoid |81 will be deenergized to allow its contacts to close. Then if contact 9| is vstill made current will be fed to wire |15 which will start motor |9 to open the face dampers. Since the switch 200 is now closed due to the energizing of the solenoid |16 solenoid |80 can establish contact through switch 200 to ground in order to start the compressor. This puts recirculated air through the sprays and the narrow dimension of the coil, thus doing sensible cooling. When the room temperature has dropped suiiiciently, contact |25 breaks causing motor |9 to close the face dampers 53 and rear dampers 54, and stopping the compressor.

Thus we can heat, cool and dehumidify in hot and humid weather. The necessity for humidifying will usually be non-existent in this weather. A falling humidity would open the face dampers and subject the recirculated air to spray and would also start the compressor. Starting the compressor would destroy the humidifying eiect so that if it were found in practice that humidifying might be necessary, a time relay could be installed which would permit the recirculation of air through the humidifyingspray without coolmg.

It is obvious that when the equipment is once placed on refrigerating operation through contact in either 86 or 81 the equipment would remain continuously in this position; namely, that shown in Fig. 10 with recirculated air passing through the cooling coil. In order to prevent the room from becoming filled with stale air a synchronous clock driven motor 200 is supplied which once each hour makes contact in the 24 volt line which completes a circuit throughline 20| to motor 20 thus returning the mechanism to ventilating operation. If the outside temperature or humidity is still too high to maintain desired room conditions the room temperature or humidity will again mount to make the high contact of thermostat |60 or hurnidostat |6|. thus returning the equipment to the refrigerating operation. Thus the equipment uses refrigeration only when maximum ventilation will not suflce and only as long as necessary since when outside conditions have returned to a cool and dry state low enough to control room temperature and humidity the use of ventilation will suiiice and the compressor may be stopped.

It is obvious that I have provided an air conditioning system which automatically controls both temperature and humidity at all times during both winter and summer seasons. 'I'he heating means operated by motor 85 is as much a part of my system as if the same were incorporated in the unit itself since all controls are placed in the recirculated or room air and the admission ot steam to the heating means is responsive to the condition of the room air.

Various operations described singularly above may be taking place at the same time, for example, the fresh air dampers may open for just a few seconds and may then close while the steam valves are being opened so that the result of the system il to maintain exact conditions within vzo the room. A recording instrument placed in an enclosure provided with my system will maintain exactly constant temperature and humidity as long as the capacity of the compressor and the capacity of the radiators is sumcient. It is obvious that during certain periods of the year the cooling eect of outside air will be suflicient to maintain accurately controlled conditions, and also at certain times the heating eiect of the compressed gas passing through the reheat coils 3l and 32 will be sufficient so that the steam heating system may be turned oir earlier in the spring and later in the fall than is usually the case. Since the demand upon the steam heating system and the refrigerating system is thus restricted to shorter periods of time a direct economy is efected.

Having described my invention it should be apparent to those skilled in the art that various alterations and modications thereof can be provided, all such as come within the scope of the following claims being a part of my invention.

I claim:

1. An air conditioning system comprising a cooling coil having cooling surfaces so constructed and arranged as to have passage-ways therethrough, said passage-ways being relatively long in one direction whereby air passing through the coil in said one direction remains in contact with said cooling surfaces for a relatively long period o1 time, and relatively short in the other direction whereby air passing through the coil in said other direction remains in contact with said cooling surfaces for a relatively short period of time, a duct for the admission of fresh air to said passage-ways and admitting fresh air thereto in the long direction thereof, a second duct for thel admission of recirculated air to said passageways and admitting recirculated air thereto in the short direction thereof, and interconnected dampers for opening one of said ducts while closing the other, said dampers being so constructed and arranged that the fresh air is confined to traverse the entire length of the coil and the recirculated air is permitted to traverse the width of the coil.-

2. An air conditioning system comprising a cooling coil having a narrow dimension and a long dimension and passages therethrough in both directions, means to admit fresh air to lsaid system, means to conne such fresh air to traverse said coil in the direction of its long dimension to be cooled and dehumidied thereby,

means to admit recirculated air to said system,

said coil.

F. BEELER. 

